1/26. Malignant peripheral nerve sheath tumor with perineurial cell differentiation (malignant perineurioma).A unique case of malignant peripheral nerve sheath tumor (MPNST) with perineurial cell differentiation occurring in a 63-year-old woman in a subcutis of the forearm is described. The tumor contained cellular and myxoid areas. The neoplastic cells were fusiform with distinct cell borders. They were arranged in storiform pattern and in wavy parallel cell cords in the cellular areas. Focally, a pleomorphism and mitotic activity (including atypical mitoses) similar to those of malignant fibrous histiocytoma were seen. The myxoid parts contained haphazardly oriented cells and scarce lipoblast-like multivacuolated cells mimicking a liposarcoma. In the differential diagnosis, myxoid liposarcoma, dermatofibrosarcoma protuberans, malignant fibrous histiocytoma and low-grade fibromyxoid sarcoma were considered. Immunohistochemically, perineurial differentiation was indicated by the diffuse expression of epithelial membrane antigen and focal reactivity for CD34. The tumor was negative with antibodies to S-100 protein, Leu-7, CD68 (KP1), vimentin and cytokeratin AE1/AE3. Ultrastructure of tumor cells revealed features of MPNST. No recurrence occurred in the patient during 2 years follow up.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/26. Intraneural perineurioma involving the median nerve.Intraneural perineurioma is a rare clinical entity, which tends to affect major nerve trunks in the upper extremities. On light microscopy, numerous pseudo-onion-bulb structures having a central clear area are surrounded by concentric layers of eosinophilic elongate cells having spindled nuclei. immunohistochemistry of concentric cells stains positive for epithelial membrane antigen but negative for S100 protein. Because of the small number of cases, no consensus has been made on proper treatment of this entity. Although none of the patients who have had excision of tumor with nerve grafting have had sensory nerve recovery, we believe each patient should be individualized until more data are available regarding this tumor.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/26. Neural fibrolipoma of the superficial peroneal nerve in the ankle: a case report with immunohistochemical analysis.This report presents a case of neural fibrolipoma arising from the superficial peroneal nerve in the ankle. A 28-year-old woman was referred with a soft tissue mass in the anterior aspect of the right ankle, which had been gradually enlarging for the past 10 years. magnetic resonance imaging showed a mass lesion, measuring approximately 8 x 3 x 2 cm, with high to partially low signal intensity on both T1- and T2-weighted images. A band of low signal intensity within the lesion, which is indicative of coexistence with the tumor and the superficial peroneal nerve, could be detected on both T1- and T2-weighted images. The patient underwent an excisional biopsy. The specimen microscopically consisted of nerve bundles and fibro-fatty proliferation with abundant collagen fibers. Immunoreactivity for CD34 antigen antibody was detected in fibrous spindle cells. This is the first report to present an immunohistochemical profile of neural fibrolipoma. Neural fibrolipoma should be considered as a differential diagnosis when a lipomatous lesion is encountered in the foot or ankle as well as in the upper extremities.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/26. Intraneural reticular perineurioma of the neck.Perineuriomas are infrequent tumors that may be intraneural or extraneural in soft tissue with no apparent relation with a nerve. Some cases of soft tissue perineurioma may have a retiform pattern, but this pattern has not been described to date in intraneural perineurioma. We report a case of a unique perineurioma arising in a nerve of the neck that had a distinctive reticular pattern and was intraneural. The patient was a 21-year-old woman who had a lump on the left side of the neck abutting the vena jugularis. The tumor had features of both reticular perineurioma and intraneural perineurioma with pseudo-onion bulb pattern. The tumor cells were positive for epithelial membrane antigen. The patient is free of tumor 6 months after operation.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/26. A case of perineurioma with prominent myxoid changes.A perineurioma with prominent myxoid changes is presented. The patient, a 41 year-old woman, presented with a small skin nodule on her back. light microscopy revealed subtle cellular whorls within a myxoid background. immunohistochemistry showed epithelial membrane antigen positivity. In contrast, S-100 protein, common leukocyte antigen, vimentin and AE1-AE3 cytokeratin were negative.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
6/26. Perineurioma: an uncommon soft tissue neoplasm distinct from localized hypertrophic neuropathy and neurofibroma.Perineurial cells, which normally surround the nerve fascicles within a nerve, can be distinguished from schwann cells by their immunoreactivity for epithelial membrane antigen (EMA) and lack of reactivity for S-100 protein. We report two cases of perineurioma, a tumor composed exclusively of perineurial cells and distinct from other nerve sheath tumors. The first case involved a deep, soft-tissue mass of the neck, and the second involved a tumor located in the infraclavicular subcutaneous tissue. Both tumors were well circumscribed. Histologically, they were hypocellular and composed of spindle cells possessing elongated nuclei and bipolar, wavy, slender, strikingly elongated cytoplasmic processes, disposed in a background of collagen in the form of short bundles and whorls. In the first case, there were frequent calcospherites and remnants of a small nerve at the periphery. The spindle cells stained for EMA but not S-100 protein, chromogranin, neuron-specific enolase or Leu-7. Ultrastructurally, they possessed long cytoplasmic processes with incomplete basal lamina and occasional pinocytotic vesicles. axons were not identified. review of the literature shows that genuine perineuriomas are rare, and most cases reported as such are merely examples of localized hypertrophic neuropathy, a mononeuropathy characterized by fusiform swelling of a nerve, usually in the extremities. The involved segment in localized hypertrophic neuropathy contains distended fascicles composed of whorls of perineurial cells and fibrous tissue entrapping residual axons, probably representing a hyperplastic reaction to nerve damage. The term perineurioma should be reserved for the neoplasm composed only of perineurial cells and presenting as a soft tissue tumor.(ABSTRACT TRUNCATED AT 250 WORDS)- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/26. Two cases of nondura-based clear cell meningioma of the cauda equina.Clear cell meningioma is a rare disorder. We report two cases of nondura-based clear cell meningioma of the cauda equina, one in a 24-year-old male and the other in a 19-year-old female. Both patients had complained of numbness and spontaneous pain in the lower back and limbs for several months. magnetic resonance imaging and computed tomography scanning revealed an intradural tumor in the cauda equina in each case. At surgery, a neurilemoma was suspected, because each of the tumors had displaced nerve roots and had attached to one of the nerve roots without any adherence to the dura. light microscopy revealed that both tumors were well-demarcated with a thin capsule and consisted mainly of clear, glycogen-rich, polygonal cells with vague whorl formations, and of copious deposits of hyalinized blocky collagen in the stroma and perivascular areas. The neoplastic cells were immunopositive for vimentin and epithelial membrane antigen, but immunonegative for S-100 protein and chromogranin a. Positive nuclei for MIB-1 were very few in both cases, and PCNA-labeling indices were 12.1% and 24.7%, respectively. No local recurrence has been seen for 61 months and for 52 months, respectively.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/26. Intraneural perineurioma involving the ulnar nerve.Intraneural perineurioma is a rare peripheral nerve sheath tumor consisting of intraneural proliferation of neoplastic perineurial cells. Clinical and pathological findings of a perineurioma involving the ulnar nerve is presented. A 7-year-old girl presented with a 2 year history of weakness and atrophy of the right hand muscles. physical examination and imaging study revealed a pea-sized tumor in the ulnar side of the right forearm. At surgery, a fusiform swelling of the ulnar nerve was found and an excisional biopsy of the lesion was performed. light microscopy revealed numerous whorls consisting of concentric layers of spindle cells encircling the nerve fibers. The proliferating cells were immunoreactive for vimentin, epithelial membrane antigen and glucose transporter protein 1 (Glut1), but negative for S-100 protein and CD34. Ultrastructural examination revealed features of perineurial cell differentiation. The current study suggests that Glut1 is a useful marker of intraneural perineurioma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/26. Immunohistochemical diagnosis of a rare case of epithelioid malignant peripheral nerve sheath tumor with multiple metastases.BACKGROUND: The epithelioid variant of malignant peripheral nerve sheath tumor (MPNST) is a rare tumor with poor prognosis that sometimes involves the head and neck. The diagnosis is based principally on the histological examination, and it is generally very difficult to reach the correct diagnosis. CASE: An 84-year-old Japanese woman presented with a tumor mass of 2 week's duration in the right medial canthal region. OBSERVATIONS: Although the tumor was excised surgically, metastases occurred three times on her face and head, and the patient died of distant systemic multiple metastases. In the histopathological analysis, the tumor showed a composite pattern comprising spindle or polygonal cells arranged in irregular bands, and a population of larger epithelioid cells in solid sheets and nests. In the immunohistochemical analysis, the tumor cells were positive for S-100 protein, vimentin, and nerve growth factor receptor (NGFR), and negative for cytokeratin and HMB 45 (melanoma-associated antigen). These findings confirmed the diagnosis of MPNST. CONCLUSIONS: Epithelioid MPNST has complex histopathological findings and histopathological features similar to other epithelioid tumors, especially malignant melanoma. Immunohistochemical examination using NGFR and HMB-45 is important in the differential diagnosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/26. November 2004: intradural mass of the cauda equina in a woman in her early 60s.November 2004. A 63-year-old woman presented with slowly aggravating lower back pain and recent urinary urge incontinence. MRI revealed a sharply-delineated, partly cystic intradural mass with inhomogenous contrast-enhancement and ectatic vessels at the upper pole. An ependymoma was suspected, and the tumor was resected in toto. Histologically, at first glance, the tumor strongly resembled an ependymoma, showing a monomorphic cellular pattern, perivascular pseudorosettes and ependymal canal-like structures. However, the finding of a delicate collagen capsule, compartmentation of tumor cells into zellballen and the presence of ganglionic cells were untypical. These features were indicative of a paraganglioma with a gangliocytic component. Immunoreactivity of the tumor cells for neuroendocrine antigens, the detection of GFAP-positive sustentacular cells and the ultrastructural confirmation of neurosecretory granules substantiated this diagnosis. The clinical, radiological and morphological similarity between ependymomas, which are far more common in the cauda equina region than paragangliomas, has led to substantial diagnostic confusion in the past.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
| | Next -> |